Principal component analysis tools to visualize matrix effects in quantitative LC-MS bioanalysis

摘要

Blood is of prime importance for bioanalysis, since samples can be easily obtained. Blood consists of figured elements suspended in plasma. The main feature of plasma is the presence of large amount of proteins. Therefore, prior to LC-MS/MS analysis, different sample preparations are currently used. The simplest method is to precipitate the proteins and isolate the supernatant. Other methods involve more complex techniques like solid phase extraction (SPE) or liquid-liquid extraction (LLE). However, after sample preparation, remaining endogenous compounds may interfere with analytes ionization and cause failure or errors in quantitative bioanalysis. Matrix effects, defined as "the direct or indirect alteration or interference in response due to the presence of unintended analytes (for analysis) or other interfering substances in the sample", are an important drawback when using protein precipitation strategy. This generally results in poor precision and accuracy and requires further method development. Matrix effects are currently assessed by two major strategies, post column infusion [1], and pre- / post spiking comparison techniques [2].